Multiquip HHN34TVD - Manual (Page 31)

HHN34TVD RIDe-ON TROWeL • OpeRaTION maNuaL — ReV. #2 (01/10/11) — page 31
Maintenance (OlD Style clutch)
As shown in Figure 22, centrifugal force pushes the roller
arms (Figure 23) against the ramp plate, forcing the
moveable face toward the fixed face and squeezing the belt
.
Figure 23. Pulley Interaction
The “Variable Pitch Pulleys” have one fixed face, and one
moveable face. The drive pulley (Figure 24) moveable face
is controlled by roller weight arms and springs, which
change position according to engine speed. The driven
pulley moveable face is controlled by a spring and belt
tension.
Figure 24. Variable Pitch Pulley
DRIVE PULLEY
LOW ENGINE RPM
HIGH ENGINE RPM
HIGH OUTPUT SPEED
LOW OUTPUT SPEED
DRIVEN
PULLEY
MOVEABLE
FACE
MOVEABLE
FACE
DISTANCE
MOVEABLE
FACE
TRAVELS
CENTRIFUGAL
FORCE
DRIVE PULLEY
DRIVEN
PULLEY
DRIVE
PULLEY
RAMP
PLATE
WEIGHT
ROLLER
ARM
SPRING
BUSHING
HOW IT WORkS
Refer to Figure 25.
Figure 25. Pulley Conditions
Condition A:
„ Engine Idling
„ Drive Pulley: Small
„ Driven Pulley: Large
„ Belt: Loose and Stationary
Condition B:
„ Engine Accelerating
„ Drive Pulley: Small But Increasing
„ Driven Pulley: Large But Decreasing
„ Belt: Approaching Tightness
Condition C:
„ Engine At High Speed
„ Drive Pulley: Large
„ Driven Pulley: Small
„ Belt: Tight
A B C
DRIVE PULLEY
DRIVEN PULLEY
NEUTRAL LOW
SPEED
HIGH
SPEED